The present invention relates generally to the art of mixing audio source signals to create a final sound product, and more specifically, to a method and apparatus for utilizing visual images of sounds to control and mix the source signals, including any sound effects added thereto, to achieve a desired sound product.
The art of mixing audio source signals is well known and generally referred to as recording engineering. In the recording engineering process, a plurality of source audio signals are input to a multi-channel mixing board (one source signal per channel). The source signals may be analog or digital in nature, such as microphone signals capturing a live performance, or a prerecorded media such as a magnetic tape deck, or a MIDI device (musical instrument digital interface) such as a synthesizer or drum machine. The mixing board permits individual control of gain, effects, pan, and equalization for each channel such that the recording engineer can modify individual channels to achieve the desired total sound effect. For example, it is possible for an individual person to record the performance of a song by recording the playing of different instruments at different times on different channels, then mixing the channels together to produce a stereophonic master recording representative of a group performance of the song. As should be obvious, the sound quality, including volume output, timbral quality, etc., of each channel can vary greatly. Thus, the purpose of the mix is to combine the different instruments, as recorded on different channels, to achieve a total sound effect as determined by the recording engineer.
The recording industry has evolved into the digital world wherein mixing boards and recorders manipulate and store sound digitally. A typical automated mixing board creates digital information that indicates mixing board settings for each channel. Thus, these mixer board settings can be stored digitally for later use to automatically set the mixer board. With the advent of MIDI control, cheaper computer controlled mixing boards have begun to appear. Such systems often include software which shows a picture of a mixing board on the computer screen, and the recording engineer often uses a mouse to manipulate the images of conventional mixing board controls on the screen. The computer then tells the mixer to make the corresponding changes in the actual mixing board.
There are also digital multitrack recorders that record digital signals on tape or hard disk. Such systems are also controlled by using a mouse to manipulate simulated recorder controls on a computer screen.
A new generation of controllers are being developed to replace the mouse for interacting with computers. For example, with a data glove or a virtual reality system one can enter the computer screen environment and make changes with their hands. Further, visual displays are becoming increasingly sophisticated such that one gets the illusion of three-dimensional images on the display. In certain devices, the visual illusion is so good that it could be confused with reality.
Computer processors have just recently achieved sufficient processing speeds to enable a large number of audio signals from a multitrack tape player to be converted into visual information in real time. For example, the Video Phone by Sony includes a Digital Signal Processor (DSP) chip that makes the translation from audio to video fast enough for real time display on a computer monitor.
The concept of using visual images to represent music is not new. Walt Disney Studios might have been the first to do so with its innovative motion picture “Fantasia.” Likewise, Music Television (MTV) has ushered in an era of music videos that often include abstract visual imaging which is synchronized with the music. However, no one has yet come up with a system for representing the intuitive spatial characteristics of all types of sound with visuals and using those spatial characteristics as a control device for the mix. The multi-level complexities of sound recording are such that very little has even been written about how we visualize sound between a pair of speakers.